This invention relates to a steering handle for an outboard motor and more particularly to a steering handle and associated controls useable in conjunction with outboard motors.
As is well known, outboard motors are highly popular types of propulsion devices for watercraft of a wide variety of types and sizes. Basically, the smaller sized watercraft are powered by smaller displacement and horsepower outboard motor and normally these outboard motors are designed with a steering tiller that is affixed to the steering shaft of the outboard motor for its steering movement and which also contains other controls for the outboard motor such as a throttle and, at times, a transmission control. The most common type of throttle control is a grip throttle control which is connected to the throttle of the engine of the outboard motor for controlling its speed.
With larger displacement outboard motors, however, it is the normal practice to employ remotely positioned controls both for the steering, throttle and transmission of the outboard motor. These controls are normally coupled from a remotely positioned control location to the various components of the outboard motor to be controlled by bowden wire cables.
There are, however, many instances wherein it is desirable to control the larger displacement, larger horsepower outboard motors from a steering tiller similar to that type of control employed with smaller displacement outboard motors. However, this type of construction presents certain difficulties which will be apparent by the description of the prior art constructions and a general description of the type of outboard motor with which the invention may be practice as will now follow by reference to FIGS. 1 through 4 of the drawings.
Referring first to FIG. 1, an outboard motor of a generally conventional type, but which may be constructed to incorporate the invention is illustrated and is identified generally by the reference numeral 21. The outboard motor 21 includes a powerhead 22 that is comprised of a powering internal combustion engine, shown diagrammatically at 23 and a surrounding protective cowling, indicated generally by the reference numeral 24 and which is comprised of a lower tray portion 25 and a detachable main cover portion 26.
As is typical with outboard motor practice, the engine 23 is supported so that its output shaft rotates about a generally vertically extending axis and is coupled to a drive shaft (not shown) that is journalled in a drive shaft housing 27 that is connected to the underside of the powerhead. This drive shaft depends through the drive shaft housing 27 into a lower unit 28 wherein a forward, neutral, reverse transmission of the conventional bevel gear type, robe described later by reference to another Figure, is provided for driving a propeller 29 in a selected forward or reverse direction.
A steering shaft 31 is affixed to the drive shaft housing 27 by upper and lower brackets 32 and 33 and is supported for steering movement within a swivel bracket 34 which steering movement occurs about a generally vertically extending steering axis. A steering arm 35 is connected to the upper end of the steering shaft 31 for the steering of the outboard motor 21 in a manner which will be described.
The swivel bracket 34 is, in turn, pivotally connected by means of a pivot pin 36 to a clamping bracket 37 for tilt and trim movement of the outboard motor 21. A clamping device 38 is connected to the clamping bracket 37 to provide a detachable connection to a hull 39 of an associated watercraft. The construction as thus far described may be considered to be conventional and, for that reason, further description is not necessary for those skilled in the art to understand both the background of this invention and the described preferred embodiments.
Referring now to FIGS. 2 and 3, a further description of the conventional construction and a conventional way in which larger displacement outboard motors are adapted for tiller control will be described. It should be noted that with a conventional construction, a transmission selector control wire 41 extends outwardly from the forward portion of the outboard motor 21 and is normally designed to be connected to a remotely positioned shift control lever. However, when conventional large displacement outboard motors are modified so as to accommodate tiller control, a shift control lever 42 will be mounted on the steering arm 35 and connected by means of a connection 43 to the wire actuator for transmission control.
In addition, a combined steering and control handle 44 is provided with a pivotal connection to the steering arm 35 about a horizontally disposed axis from an operative position as shown in FIGS. 1 and 2 to an elevated storage position. This steering control 44 includes an outer housing assembly 45 with a twist grip throttle 46 rotatably journalled at its outer end for rotation about a longitudinal axis 47 in directions indicated by the arrow 48.
Contained within the interior of the steering handle body 45 is a shaft 49 to which the throttle control 46 is connected. A pulley 51 is affixed to this shaft 49 and has a wire actuator 52 encircling it which is connected to a throttle control wire actuator 53 of the outboard motor 21. The wire actuator 53 is normally designed to be connected to a remote throttle mechanism and in order to accommodate tiller control as shown in the drawings, it is necessary to bend the cable 53 through a fairly substantial angle and this provides not; only an unsightly appearance, but also an extending member that can become entangled with various paraphernalia which may be used by the users of the watercraft such as fishing line, nets or the like. Clearly, this is not a satisfactory arrangement.
FIG. 4 shows another prior art way of converting a conventional larger displacement outboard motor into tiller control. Again, the tiller control is identified generally by the reference numeral 44A and where components are the same as the type of prior art construction shown in FIGS. 2 and 3, they have been identified by the same reference numerals. However, where the components are different, they will be identified by the same reference numerals with the suffix "A" added. In this embodiment, the handle assembly 45A also supports a twist grip throttle 46 which, in this type of construction, is connected to a shaft 49A having a helical screw element 51A connected to it. This screw element 51A cooperates with a follower 54 that is affixed to the forward end of the throttle control 53 and which has a groove 56 that cooperates with the helical member 58 so as to reciprocate the control wire 53 upon rotation of the throttle grip 46. Although this type of arrangement provides a neater appearance, the screw and nut connection does not afford a significant degree of mechanical advantage due to the amount of reciprocal motion must be generated for a relatively small amount of rotary motion. Therefore, this type of twist grip throttle requires high operational forces and is not at all satisfactory.
It is, therefore, a principal object to this invention to provide an improved steering handle assembly for outboard motors.
It is a further object to this invention to provide an improved steering handle and control assembly for outboard motors that may be utilized with large displacement outboard motors that are normally designed to be operated remotely and to convert these into tiller operation.
It is a further object to this invention to provide an improved arrangement for affording a neat compact and yet extremely useful tiller control for a large displacement outboard motor.
As has been previously noted, most outboard motors, particularly those of larger displacement, employ a forward, neutral, reverse transmission in addition to throttle control and steering control. These transmissions are conventionally bevel gear type transmissions that are operated by dog clutches. Of course, the dog clutching mechanism is an all-on or all-off type of device and can result in sudden impact with shifts occur and also abrupt movements.
The inherent problems with the transmission coupled with the fact that the throttle controls normally are designed to stay in a fixed position if the operator releases them can give rise to certain problems. Therefore, it is conventionally the practice to incorporate within the body of the outboard motor a interlock mechanism between the transmission and throttle control which limits the speed at which the engine can be driven when in certain gears or which, alternatively, blocks shifting when the throttle control is opened too widely. However, these types of arrangements when positioned inside of the casing of the outboard motor do not afford ease of adjustment. Furthermore, when a large displacement outboard motor is adapted to accommodate a tiller control, the mechanism normally employed for controlling the interrelationship of engine speed and transmission control is not acceptable.
It is, therefore, a still further object to this invention to provide an improved combined throttle and transmission control for an outboard motor wherein the speed of the throttle is limited in relation to the transmission condition.